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Fear and denial as infections soar

By PHYLLIDA BROWN

While the world’s leaders continue to deny the magnitude of the threat,
there is little hope of controlling the AIDS epidemic, public health experts
warned as the tenth international conference on AIDS began this week in
Yokohama. But, they argued, even modest spending could avert millions of
new infections in regions where the virus is now spreading most rapidly.

Despite the best efforts of health educators and researchers, more people
were infected with the virus in the past 12 months than in any previous
year, said Michael Merson, head of the WHO’s global programme on AIDS. The
estimated total number of infections since the early 1980s has jumped from
14 million last year to 17 million this year. In India alone, the number
has trebled since 1992.

In China, an HIV epidemic looms. The number of people infected with
other sexually transmitted diseases has climbed sharply as the economy booms
and millions of people migrate for new jobs.

‘If we know so much about preventing AIDS, why is the epidemic continuing
to expand?’ asked Merson. He suggested three reasons. ‘Denial is what keeps
society’s leaders from taking the pandemic seriously and investing the resources
needed,’ he said. Secondly, discrimination by governments against HIV-positive
people, for example in mandatory testing, is ‘at best futile and often harmful
to true prevention’. And thirdly, the most vulnerable people are deprived
of the information and power to protect themselves from infection.

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Cost is not the issue, he says. The WHO calculates that the cost of
implementing basic HIV prevention programmes in Asia and averting 5 million
infections before the end of the decade is at most $1.5 billion a year
– an amount that Japan’s workers produce in less than an hour.

Governments need to invest in prevention and research for new drugs
and a vaccine, and fill the ‘colossal gaps’ in health services that leave
many of the world’s people with AIDS without care. ‘Political leaders must
find the courage to provide leadership . . . and discriminatory laws must
be abolished,’ said Merson.

In rare cases where AIDS is taken seriously, the effect is measurable,
he said. In Thailand, for example, reported cases of sexually transmitted
diseases dropped by more than 75 per cent between 1986 and 1993. Epidemiologists
believe the fall is the result of intensive HIV education in groups at risk
and the mass promotion of condoms. ‘Thailand is one of the few countries
putting impressive national resources into AIDS prevention and it is getting
impressive results,’ said Merson.

But persuading people to use condoms is not the whole answer. Vaccines
are crucial too, says William Paul, the new head of the Office of AIDS Research
at the US National Institutes of Health. In his first address since taking
control of the OAR’s $1.3 billion budget, Paul told the conference that
vaccines remain a high priority for the NIH despite the US’s recent decision
to defer large-scale trials of the first generation of vaccines (This Week,
25 June). ‘The only way that HIV can possibly be eradicated is by vaccines,’
Paul told New Scientist. ‘Far from having given up, we are going to make
a serious attempt at second-generation vaccines.’ He said the search must
include the possibility of using live, weakened forms of HIV to protect
people from the real virus. Some critics fear that such vaccines would be
dangerous, but Paul says their benefits might outweigh their risks where
HIV is spreading rapidly.

Paul also set out to reassure scientists who feared that the OAR would
wield too much power over their work. The office was set up last year after
AIDS activists lobbied the Clinton administration for a ‘Manhattan project’
to tackle AIDS. But Paul said that the power to initiate research would
remain with scientists. ‘A Manhattan project assumes that you know what
the questions are,’ he told New Scientist. With basic AIDS research, ‘we
still don’t know the critical questions to ask’.

But one key question is why some people with HIV remain healthy for
more than a decade while others develop AIDS. Anthony Fauci, head of the
US National Institute of Allergy and Infectious Diseases, offered some suggestions
this week. On the face of it, his conclusions appear obvious: some individuals
fight off the virus better than others. The hard questions to answer are
how and why. ‘We don’t know, but we are certainly further along than a year
ago,’ says Fauci. Fauci’s team has already shown that the lymph nodes of
HIV-positive people are packed with HIV particles even when none can be
detected in their blood. The virus appears to destroy the lymph tissue then
overwhelms the immune system. Now, the team has studied a small number of
people who are still healthy more than 10 years after becoming infected.
They show no sign of disease, nor do they show the characteristic decline
in the number of T cells that signals disease. Studies of their lymph nodes
brought an even greater surprise: the tissue is ‘perfectly normal’, says
Fauci. In some cases, this could be explained by a defective virus causing
the infection, says Fauci. But often the virus was capable of replicating
quite normally.

The work by Fauci and his colleagues overturns earlier ideas about the
kind of immune response that protects against disease. For example, their
studies showed that no particular group of T-helper cells is linked with
staying healthy or progressing to disease. And those who stayed healthy
for a long time had high levels of antibodies to the virus, once thought
to indicate a failing immune system.